After more than five years at the helm, Rovio co-founder Mikael Hed is stepping down from his CEO position, and will instead oversee animation and movie operations at the company.

Finland-based Rovio, the maker of the Angry Birds mobile game, said it has hired Pekka Rantala from beverage maker Hartwall to take over as its new chief executive by the beginning of next year.

Hed, son of board chairman and co-founder Kaj Hed, will join the company’s board of directors as well as take on the role of chairman at Rovio’s animation studios.

Rantala, who is currently the CEO of Hartwall, earlier worked for 14 years for Nokia.

After scoring a global breakthrough with Angry Birds in which players use a slingshot to attack pigs who steal birds’ eggs, Rovio has expanded the brand into an animated TV series and merchandising of toys and clothing.

But it has struggled to retain players and earnings halved last year due to investments in the animation business as well as stalling sales.

Rovio said several years ago it could go public in Hong Kong or New York, but has later said it was not planning an initial public offering any time soon.